Speaker design



March 8, 1966 R. NAMN SPEAKER DESIGN Original Filed April 29. 1960 2Sheets-Sheet 1 IN VEN TOR.

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SPEAKER DESIGN Original Filed April 29, 19

6`O`/ 2 Sheets-Sheet 2 42]@ QJ@ 4Z] 35 3 43@ l JNVENTOR. Mam /l/zmomUnited States Patent O 3,239,029 SPEAKER DESIGN Richard Namen, 9515Nassau Drive, Miami, Fla. Original application Apr. 29, 1960, Ser. No.25,694, now Patent No. 3,107,746, dated Oct. 22, 1963. Divided and thisapplication Aug. 19, 1963, Ser. No. 303,064

2 Claims. (Cl. 181-32) This invention relates to transducers and inparticular to high fidelity speakers.

This application is a division of my co-p-ending application Ser. No.25,694 filed Apr. 29, 1960, entitled Speaker Design, now U.S. Patent No.3,107,746.

In the known speaker constructions, increased fidelity has required theprovision of complex speaker structures and accurately coordinated andrelatively expensive speaker enclosures. Further, the limited angle ofsound dispersion produced by the known speakers has been a seriousproblem because of the highly directional characteristics thereof.

The present invention is concerned with a new and improved speakereliminating the above discussed disadvantages of the known speakers. Ap-rime feature of the present invention is, therefore, the provision ofa new and improved transducer providing improved high fidelityoperation.

Another feature of the invention is the provision of such a transducercomprising a flexible wall member having a mid-portion and edge portionson opposite sides of the mid-portion, first resilient means urging theedge portions toward each other and resultingly urging the midportion ina first direction transversely to a line between the edge portions,second resilient means urging the midportion in a second directionopposite to the first direction and resultingly urging the edge portionsaway from each other to balance the urging of the first resilient means,means precluding movement of the edge portions in the second direction,and means reciprocating one of (a) the mid-portion in the first andsecond directions and (b) an edge portion toward and from the other edgeportion to flex correspondingly substantially the entire wall member.

A further feature of the invention is the provision of such a transducerwherein the exible wall member comprises a plate, the resilient meanscomprise spring elements, and the reciprocating means comprises a voicecoil reciprocating the wall member at sonic frequencies.

Still another feature of the invention is the provision of a new andimproved transducer comprising a iiexible wall member having amid-portion and edge portions on opposite sides of the mid-portion,support means carrying the -edge portions for pivotal movement about apair of spaced, parallel axes to move toward and away from each otherand resultingly urging the mid-portion in a first direction transverselyto a line between the edge portions, resilient means urging themid-portion in a second direction opposite to the first direction, andmeans pivotally reciprocating the support means to reciprocate the edgeportions toward and from each other to liex correspondinglysubstantially the entire wall member.

Other features and advantages of the invention will be apparent from thefollowing description taken in c-onnection with the accompanyingdrawings, in which:

FIGURE 1 is a front elevation of a transducer embodying the invention;

FIGURE 2 is a vertical section thereof taken substantially along theline 2-2 of FIGURE 1;

FIGURE 3 is a transverse section thereof taken substantially along theline 3 3 of FIGURE l;

FIGURE 4 is a diagrammatic elevation of the wall member of thetransducer;

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FIGURE 5 is a diagrammatic plan view thereof;

FIGURE 6 is a diagrammatic plan view of another form of wall member foruse therein;

FIGURE 7 is an elevation of still another form of wall member for usetherein;

FIGURE 8 is a transverse section taken substantially along the line 8 8of FIGURE 7;

FIGURE 9 is a fragmentary plan view of another form of transducerembodying the invention; and

FIGURE 10 is a fragmentary plan view of still another form of transducerembodying the invention.

In th-e exemplary embodiment of the invention as disclosed in FIGURES 1through 5 of the drawings, a transducer generally designated 10comprises a flexible plate wall member 11 having a mid-portion 12 andedge portions 13 and 14 disposed on opposite sides of the midportion 12.Herein the plate 11 is segmentally cylindrical whereby the mid-portion12 is displaced transversely from a line A-A drawn between the edgeportions 13 and 14 (see FIGURE 5). The edge portions 13 and 14 areslidably carried on a pair of spaced supports 15 and 16, respectively,and are urged toward each other by a pair of resilient blocks 17 and 18,respectively, carried on a rigid frame 19.

As a result of the urging together of the edge portions 13 and 14 by thespring blocks 17 and 18, the mid-portion 12 of the plate 11 is urgedaway from line A-A along a transverse plane B-B in the direction of thearrow C in FIG. 5. This urging force is balanced by a counteractingspring 20 compressed between a transverse support 21 carried by frame 19and the mid-portion 12 of the plate 11. Herein, the characteristics ofspring 20 are coordinated with the characteristics of the spring blocks17 and 18 so that the plate 11 is urged to its unbiased segmentallycylindrical configuration against the balancing action of the springblocks.

Extending forwardly from the front face 22 of the plate mid-portion 12is a voice coil 23 cooperating with a magnet 24, herein a permanentmagnet, carried on frame 19 to reciprocate the plate mid-portion 12 as afunction of an alternating electrical current passed through the voicecoil 23. The deflection of the plate mid-portion 12 causes acorresponding movement of the edge portions 13 and 14 toward or awayfrom each other along the line A-A depending on which direction alongplane B B mid-portion 12 has moved from the static position of FIG- URE2. Thus, when the mid-portion 12 is urged toward frame 19 the edgeportions 13 and 14 are urged apart against the balancing action ofspring blocks 17 and 18. When the mid-portion 12 is urged away from theframe 19 against the action of spring 20 the edge portions 13 and 14 areurged toward each other along the line A-A. Resultingly the entire platemember 11 is driven at the frequency of the current in voice coil 23;where the current alternates at a sonic frequency the plate 11 functionsas a high fidelity speaker diaphragm faithfully reproducing theelectrical current as sound Waves in the air surrounding the transducer.

As illustrated in FIGURE 5, the angle gb between the line A-A and a line25 drawn between an edge portion, as edge portion 14, and themid-portion 12 is preferably relatively small, in the range ofapproximately 5 or less. With such a small angle, the force relationshipbetween the forces acting on the mid-portion along the plane B-B and theforces acting on the edge portions along the line A-A is given by theformula, forces (B-B) equal forces (A-A) tangent e. Thus, illustrativelywhere 1: equals 5 the forces in plane B-B need be only .087 times theforces along line A-A for a balance thereof. Further, as a result of thesmall angle g5, the movement of the edge portions 13 and 14 along theline A A corresponding to a given movement of the mid-portion 12 alongthe plane B-B is relatively small.

In effect, the plate 11 vibrates in the direction of line A-A as Well asin the direction of the plane B-B although to a somewhat lesser extend.The resultant direction of motion of the sound propagation is not inalignment With either the line A-A or plane B-B but rather at an anglethereto. To utilize the sound producing effect of plate 11 mosteiciently, it is desirable to provide the forward surface thereof with aplurality of grooves having the faces thereof substantiallyperpendicular to the effective sound propagation direction. Thus,referring now to FIGURE 6, a modified form of plate 111 is shown tocomprise a flexible wall member 111 generally similar to plate 11 butprovided on the front surface thereof with a plurality of groovesgenerally designated 125 each having a first surface 126 extendingparallel to the direction of the resultant motion .of the plate and asecond surface 127 extending perpendicular thereto. By virtue of thegrooves 125, plate 111 is capable of producing an extended frequencyrange of sound having a wide dispersion comparable to, and in some casesexceeding, the dispersion characteristics of multispeaker installations.

Referring now to FIGURES 7 and 8, another form of plate wall member 211is shown to comprise a flat plate having a reinforcing bar 228 extendinglongitudinally along and rearwardly from the center of the rear surface229 of the plate. Thus reinforced, plate member 211 may be ofsubstantial size such as six feet or longer in length.

Referring now to FIGURE 9, a portion of another modified form oftransducer 310 is shown to comprise a flexible plate wall member 311having end portions 313 and 314 slidably supported on fixed supports 315and 316 respectively, and having secured thereto voice coils 330 and 331respectively. Voice coil 330 cooperates with a suita-ble magnet 332 andvoice cail 331 cooperates with a corresponding suitable magnet 333 toreciprocate the plate 311 by applying reciprocating opposing forces tothe edge portions of the plate in the direction corresponding to theline A-A of plate 11. As the edge portions travel a distance especiallyless than the distance travelled by the mid-portion 312 of plate 311,extremely linear electro-mechanical conversion is obtained. While thevibration travel of the voice coil 330 and 331 is not linear withrespect to the balanced position of the plate 311, the amplitude of thevibration of the plate in the direction of the maximum sound propagationwill be accurately linear.

In FIGURE 10, a portion of still another transducer 410 is illustratedas comprising a flexible wall member plate 411 having its edge portions413 and 414 pivotally secured by means of pins 434 and 435 respectivelyto a pair of corresponding pivot wheels 436 and 437. Wheel 436 pivotsabout an axis 43S parallel to an axis 439 about which Wheel 437 pivots,the axes 438 and 439 extending parallel to the direction of soundpropagation of the plate 411. The wheels 426 and 437 are rotativelyreciprocated by suitable transducer means (not shown) in correspondencewith an electrical signal to move the plate edge portions 413 and 414alternately toward and from each other in correspondence with theelectrical signal to flex the plate 411 suitably for reproducing thesignal in the form of sound.

In each yof the fragmentary showings of the different forms oftransducer structures embodying the invention, only those elementsdiffering from the elements of transducer 10 have been illustrated todisclose most clearly the different forms. Thus, except as -otherwisenoted, each Iof the different structures functions in a generallysimilar manner to produce an improved high fidelity sound reproduction.

Through use of the improved transducer structure herein disclosed, ahigh fidelity speaker is obtained without need for cooperating enclosuremeans. Extremely wide dispersion of the sound may be effected byproducing the speakers disclosed herein in large sizes; illustratively,the plate may be six feet long by six inches high and may be driven by asuitable number of voice coils. The inherent rigidity of the platepermits high power outputs with effectively minimized distortion over anextended frequency range, as for example 5-50,000 cycles per second. Thesimplified construction permits the speaker to be produced at extremelylow cost and effectively eliminates maintenance problems.

Having described my invention in considerable detail, it is my intentionthat the invention be not limited by any of the details or descriptionunless otherwise specified, but rather be construed broadly within thespirit and scope as set out in the accompanying claims.

Iclaim:

1. A transducer comprising, a flexible Wall member having a mid-portionand edge portions on opposite sides of said mid-portion, opposed supportmeans carrying each of the edge portions for movement toward and awayfrom the other edge portion and resultingly urging said mid-portion in adirection transversely to a line between said edge portions, meansconnected to each edge portion and operable in unison for reciprocatingthe edge portions toward and away from each other to ex correspondinglysubstantially the entire wall member to move said mid-portion in saiddirection.

2. A transducer comprising, a flexible wall member having a mid-portionand edge portions on opposite sides of said mid-portion, support meanscarrying opposite edge portions for movement toward and away Ifrom eachother and resultingly urging said mid-portion in a directiontransversely to a line between said opposite edge portions, meansincluding a voice coil connected to each of the last mentioned edgeportions for reciprocating such edge portions toward and away from eachother along said line to flex correspondingly substantially the entirewall member to move said mid-portion in said direction.

References Cited by the Examiner UNITED STATES PATENTS 1,560,502 11/1925De Forest 181-31 X 1,577,920 3 /1926 Mansbendel 181-32 1,667,149 4/ 1928Gerlach 181-31 X 1,683,178 9/1928 Gibbs 181-31 1,735,860 11/1929Hutchinson 181-31 1,770,490 7/ 1930 Meissner.

1,786,465 12/1930 Van Wagenen 181-31 X 1,790,528 1/1931 Babcock 181-321,885,308 11/1932 Thomas 181-31 1,958,423 5/1934 Duffy 181-31 2,548,2354/ 1951 Olson.

LEO SMILOW, Primary Examiner.

1. A TRANSDUCER COMPRISING, A FLEXIBLE WALL MEMBER HAVING A MID-PORTIONAND EDGE PORTIONS ON OPPOSITE SIDES OF SAID MID-PORTION, OPPOSED SUPPORTMEANS CARRYING EACH OF THE EDGE PORTIONS FOR MOVEMENT TOWARD AND AWAYFROM THE OTHER EDGE PORTION AND RESULTINGLY URGING SAID MID-PORTION IN ADIRECTION TRANSVERSELY TO A LINE BETWEEN SAID EDGE PORTIONS, MEANSCONNECTED TO EACH EDGE PORTION AND OPERABLE IN UNISON FOR RECIPROCATINGTHE EDGE PORTIONS TOWARD AND AWAY FROM EACH OTHER TO FLEXCORRESPONDINGLY SUBSTANTIALLY THE ENTIRE WALL MEMBER TO MOVE SAIDMID-PORTION IN SAID DIRECTION.